Ferdinando Corriere

ESTIMATION OF AIR POLLUTANT EMISSIONS IN FLOWER ROUNDABOUTS AND IN CONVENTIONAL ROUNDABOUTS

Abstract The road pollutant emissions, above all in urban context, are correlated to many infrastructural parameters and to traffic intensity and typology. The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety, like the flower roundabouts (in which right-turn manoeuvres do not conflict with the circulating flow). The main objective of this paper is to propose a model for the estimation the capacity, delay, levels of service and the pollutant emissions into flower roundabouts. A comparative analysis between conventional roundabout and flower roundabout has been carried out in terms of CO, CO2, CH4, NO, PM2,5 and PM10 vehicular emissions, evaluated by mean of COPERT Software which is developed as a European tool for the calculation of emissions from the road transport sector.

Estimation of Air Pollutant Emissions in “Turbo” and in Conventional Roundabouts

The road pollutant emissions, above all in urban context, are correlated to many infrastructural parameters and to traffic intensity and typology. The research work on road junction geometry, carried out in European research centres, has recently allowed to design new road intersection types which are of undoubted interest, especially in terms of traffic functionality and safety, like the turbo roundabouts (in which right-turn manoeuvres do not conflict with the circulating flow). The main objective of this paper is to propose a model for the estimation the performances and the pollutant emissions into turbo roundabouts. A comparative analysis between conventional roundabout and turbo roundabout has been carried out in terms of CO, CO2, CH4, NO, PM2,5 and PM10 vehicular emissions, evaluated by mean of COPERT Software which is developed as a European tool for the calculation of emissions from the road transport sector.

A LOGIC FUZZY MODEL FOR EVALUATION OF THE RAILWAY STATION'S PRACTICE CAPACITY IN SAFETY OPERATING CONDITIONS

Abstract The practice capacity of a railway junction depends, in addition to the effective operation’s conditions, by the potential risk factors related to the design plan of the railway station. With the aim of an approach based on the “fuzzy sets” it is possible to determine the numeric value of the practice capacity by the logic - qualitative relations between the features of the railway junction and the potential risk factors. This methodology permits to try out the absolute value of a suitable vector β, (less then the unit) for the utilization of the theoretic capacity in conditions of maximum reliability of the system related to the aspect of safety (technique “fail safe”).

Environmental Implications of Traffic Flow Delays: a Model for Urban Streets

In this paper the problem of roads capacity is dealt in presence of perturbations of the vehicular flow. In particular, among the different disturbing causes, it is here considered the presence of vehicles parked along the road in relation to their parking activity. Having already established the delay, caused by those vehicles leaving their stationary positions and entering the traffic flow or by those who slow down the flow to park, it is possible to evaluate the changes in time running values. Related to these times delay, the extra pollutant emissions by a given urban running fleet is also evaluated, by utilizing emission factors depending on age, type, volume capacity and engine of the vehicles.

Handling Underdispersion in Calibrating Safety Performance Function at Urban, Four-Leg, Signalized Intersections

Poisson basic assumption of equidispersion is often too much restrictive for crash count data; in fact this type of data has been found to often exhibit overdispersion. Underdispersion has been less commonly observed, and this is the reason why it has been less convenient to model directly than overdispersion. Overdispersion and underdispersion are not the only issues that can be a potential source of error in specifying statistical models and that can lead to biased crash-frequency predictions; these issues can derive from data properties (temporal and spatial correlation, time-varying explanatory variables, etc.) or from methodological approach (omitted variables, functional form selection, etc.). This article focuses on the potential of the Conway-Maxwell (COM-Poisson) model in handling underdispersion that arose in the development of a Safety Performance Function for urban four-leg signalized intersections; other issues, as temporal data correlation, have been intentionally eluded to test the best way of handling underdispersion. Results confirmed that the COM-Poisson model properly handled crash data set for which neither Poisson nor negative binomial model were able to account for dispersion phenomenon; they also showed that the COM-Poisson model provided a good statistical performance and a better goodness-of-fit than the quasi-Poisson and the traditional Poisson model.

Estimation of Measures of Effectiveness (MOE) for the C-Roundabouts

The C-roundabout (cyclist roundabout) is a new multi-lane roundabout designed to improve the safety of cyclists at and make multi-lane roundabouts more cyclist-friendly. The geometric layout of C-Roundabouts allows the decrease of the vehicle speeds through the roundabout to around 30 km/h. The rare C-roundabout installations so far implemented in the world have not allowed analysing the capacity by means empirical data. In the light of this considerations, the main objective of the paper is to give a theoretical closed-form model for evaluation the measures of effectiveness MOE (capacity, delay, queues) of the C-Roundabouts.

Reducing Air Pollutants through Road Innovative Intersections

Road pollutant emissions are correlated mainly to infrastructural capacity and to traffic intensity and typology. With the aim to improve road intersections performances in the last years was designed many new geometric layouts, like turbo roundabouts and flower roundabouts. The main objective of this paper is carried out a comparative analysis between conventional and innovative roundabouts in terms of CO, CO2, NO and PM2,5 vehicular emissions, evaluated by means of COPERT Software which is developed as a European tool for the calculation of emissions from the road transport sector.

Calculation of Turbo-Roundabouts with Slip Lanes

A turbo roundabout is a particular type of roundabout where all lanes are bounded by traffic signs and by non-mountable curbs installed at entering and circulating lanes. Turbo roundabouts also have a very particular shape to accomplish the splitting of traffic streams and to prevent cars weaving through. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. Only in some traffic conditions, turbo roundabouts can offer higher capacities than conventional double-lanes roundabouts, so if more capacity must be guarantee a bypass lane can be added to the turbo roundabouts layout. This paper presents a closed-form model for the estimation of capacity, delays and level of service of turbo-roundabout equipped with Right-turn bypass lanes, considering the effect of geometric slip lane schemes, control type, vehicular and pedestrian flow.

Characterization of Biodiesel from Vegetable Oil Using Comprehensive Two-Dimensional Gas Chromatography

Biodiesel from vegetable oils has been analyzed and its suitability for internal combustion engines has been assessed. The Standard biofuel’s characteristics have been investigated. Gas chromatography (GC) tests were carried out to characterize the fatty acid behavior. It was found that the mass percentage of saturated fatty acids did not change substantially with time, while unsaturated fatty acids increased with time for both B100 and B30. An increase in density for B100 and B30 with time was noted. Biodiesel density was within the standardization. The calorific values of biodiesel and its blend increased with time. Higher heating value for B100 increased from 41 to 43 MJ/kg while B30 increased from 44 to 45 MJ/kg.